ipfilter 实锟斤拷透锟斤拷锟斤拷锟斤拷
April 20, 2002 href="mailto:[email protected]">Charley Sense
(锟斤拷锟侥匡拷锟斤拷锟斤拷锟斤拷转锟截ｏ拷锟斤拷注锟斤拷锟斤拷锟竭和筹拷锟斤拷)
锟斤拷锟斤拷(锟斤拷锟斤拷)锟斤拷锟斤拷锟斤拷锟斤拷路, 锟斤拷学习锟斤拷没锟斤拷锟斤拷, 锟秸革拷锟斤拷锟斤拷锟揭惶拷锟斤拷锟斤拷锟斤拷锟斤拷锟�, 锟斤拷锟节革拷锟斤拷锟斤拷锟斤拷实锟斤拷锟斤拷小锟斤拷一锟斤拷, 锟斤拷没锟斤拷什么锟斤拷锟斤拷值锟斤拷锟斤拷耀锟斤拷. 应
href="http://www.linuxforum.net">锟叫癸拷Linux锟斤拷坛 FreeBSD锟斤拷锟斤拷锟斤拷锟�
href="mailto:[email protected]">r00t 锟斤拷要锟斤拷, 锟斤拷锟斤拷锟矫癸拷锟斤拷锟斤拷锟斤拷一锟斤拷锟斤拷录, 锟斤拷锟斤拷锟斤拷笑锟斤拷.
锟斤拷锟斤拷锟斤拷锟斤拷什么锟斤拷锟斤拷, 锟斤拷锟斤拷锟斤拷锟斤拷
锟斤拷系. 锟斤拷锟斤拷锟斤拷锟截斤拷锟斤拷锟斤拷锟斤拷透锟斤拷锟斤拷锟斤拷, 锟斤拷锟斤拷锟斤拷锟芥及锟斤拷锟斤拷锟斤拷锟斤拷锟�, 锟斤拷dns, web, email锟斤拷锟斤拷锟斤拷, 锟斤拷些锟斤拷锟斤拷锟斤拷锟斤拷锟节凤拷锟斤拷墙锟斤拷要锟斤拷, 锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷锟�.
锟斤拷锟矫憋拷锟斤拷锟斤拷锟斤拷, 锟斤拷锟斤拷锟斤拷锟轿猴拷锟斤拷失, 锟斤拷锟竭概诧拷锟斤拷锟斤拷.
IP Filter Based Firewalls HOWTO [
href="http://www.obfuscation.org/ipf/ipf-howto.pdf" target=_blank>PDF
|
target=_blank>HTML ] (锟斤拷锟斤拷锟叫硷拷锟� HOWTO)
target=_blank>Quick CableNet Connections with FreeBSD - By, Leon
系统锟斤拷装FreeBSD 4.5. PENTIUM-S 100, 80M锟节达拷, 4G硬锟斤拷. 锟斤拷装双锟斤拷锟斤拷.
锟斤拷锟斤拷锟斤拷锟斤拷时锟斤拷为Client, 锟斤拷装Windows XP
Gateway dc0锟斤拷锟斤拷锟街�192.168.0.1/24, 通锟斤拷HUB锟斤拷锟斤拷锟斤拷锟斤拷Windows XP锟酵伙拷锟斤拷
192.168.0.4/24, vr0锟斤拷锟斤拷ADSL Modem, 通锟斤拷pppoe锟斤拷锟斤拷锟斤拷锟斤拷.锟斤拷锟矫讹拷态锟斤拷址.
锟斤拷锟侥假讹拷Gateway 锟斤拷 pppoe锟斤拷DNS锟窖撅拷锟斤拷锟斤拷锟斤拷锟斤拷, 锟叫癸拷锟解方锟斤拷慕锟斤拷锟�, 锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷锟�.
cd /usr/src/sys/i386/conf
cp GENERIC KERNEL1
vi KERNEL1
锟睫改革拷锟节猴拷锟斤拷锟斤拷锟侥硷拷, 锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷
options IPFILTER
# ipfilter support
options IPFILTER_LOG
# ipmon(8) log support
options IPFILTER_DEFAULT_BLOCK
# block all packets by default
options RANDOM_IP_ID
# RANDOM_IP_ID causes the ID field in IP packets to be
randomized
# instead of incremented by 1 with each packet generated.
options BRIDGE
options ICMP_BANDLIM
# Rate limit bad replies
#options TCP_DROP_SYNFIN
# drop TCP packets with SYN+FIN
# 锟矫诧拷锟斤拷锟斤拷锟斤拷锟斤拷锟较低筹拷陌锟饺拷裕锟斤拷锟斤拷锟斤拷锟絯eb server时锟斤拷锟斤拷锟斤拷使锟矫ｏ拷锟斤拷锟絃INT
取锟斤拷锟节猴拷锟斤拷锟斤拷锟斤拷锟斤拷IPFIREWALL锟叫关碉拷锟斤拷锟斤拷
# options IPFIREWALL
# firewall
# options IPFIREWALL_VERBOSE
# enable logging to syslogd(8)
# options IPFIREWALL_FORWARD
# enable transparent proxy support
# options IPFIREWALL_VERBOSE_LIMIT=100
# limit verbosity
# options IPFIREWALL_DEFAULT_TO_ACCEPT
# allow everything by default
# options DUMMYNET
锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷锟�
options NMBCLUSTERS=32768
系统锟斤拷装时锟矫诧拷锟斤拷锟斤拷小, 锟斤拷影锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷锟�. 锟斤拷锟斤拷锟街抵伙拷锟斤拷壹虻サ锟斤拷锟斤拷锟�, 锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷要锟斤拷锟斤拷. 锟斤拷锟斤拷说锟斤拷锟斤拷锟� href="http://www.freebsd.org/doc/en_US.ISO8859-1/books/handbook/index.html" target=_blank>FreeBSD HandBook "http://www.freebsd.org/doc/en_US.ISO8859-1/books/handbook/configtuning-kernel-limits.html" target=_blank>6.10.2 Network Limits
锟斤拷示锟斤拷锟节猴拷
ident KERNEL1
锟斤拷锟斤拷锟节猴拷
cd /usr/src
make buildkernel KERNCONF=KERNEL1
make installkernel KERNCONF=KERNEL1
(锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷院喜锟轿� make kernel KERNCONF=KERNEL1)
删锟斤拷锟斤拷锟侥硷拷锟斤拷锟叫癸拷ipfw锟斤拷锟斤拷锟斤拷, 锟斤拷锟竭斤拷
firewall_enable="NO"
锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷
gateway_enable="YES"
# enable gateway
named_enable=YES"
# enable naming service
ipfilter_enable="YES"
# Stateful firewall
ipfilter_program="/sbin/ipf"
ipfilter_rules="/etc/ipf.conf"
# 锟斤拷锟斤拷锟接的癸拷锟斤拷锟侥硷拷, 锟斤拷锟斤拷习锟斤拷锟侥硷拷锟斤拷 .rule
ipfilter_flag=""
ipnat_enable="YES"
# Network Address Translation
ipnat_program="/sbin/ipnat"
ipnat_rules="/etc/ipnat.conf"
# 锟斤拷锟斤拷锟接的癸拷锟斤拷锟侥硷拷, 锟斤拷锟斤拷习锟斤拷锟侥硷拷锟斤拷 .rule
ipmon_enable="NO"
# Firewall logging, 锟斤拷没锟叫匡拷锟斤拷, 锟斤拷锟斤拷锟斤拷锟揭拷姆锟斤拷锟斤拷锟�, 应锟矫匡拷锟斤拷.
ipmon_program="/sbin/ipmon"
ipmon_flag="-Ds"
锟斤拷锟侥硷拷为锟斤拷锟斤拷墙锟斤拷锟斤拷锟侥硷拷, 锟斤拷锟斤拷锟斤拷要锟斤拷锟斤拷实锟斤拷透锟斤拷锟斤拷锟斤拷, 锟斤拷锟斤拷锟斤拷慕嵌冉锟斤拷谴锟斤拷锟紺lient, 锟斤拷斯乇锟斤拷锟絀nternet锟斤拷锟斤拷锟絊erver
In锟斤拷锟斤拷锟叫端匡拷. 锟斤拷锟斤拷锟斤拷锟�, 锟斤拷锟斤拷锟斤拷锟斤拷dc0锟斤拷锟斤拷锟叫诧拷锟斤拷, 锟斤拷锟斤拷锟斤拷锟斤拷Internet锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷, 锟斤拷锟斤拷锟斤拷Internet只锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷幕锟接�, 锟斤拷锟斤拷锟斤拷一锟缴讹拷锟斤拷.
# 默锟较癸拷锟斤拷, 锟截憋拷锟斤拷止锟斤拷锟叫的帮拷, 锟截憋拷锟斤拷锟叫碉拷通路, 锟斤拷一锟斤拷一锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷通锟斤拷.
# 锟斤拷锟斤拷诤锟斤拷锟斤拷锟斤拷锟� IPFILTER_DEFAULT_BLOCK, 锟斤拷锟斤拷省锟斤拷.
block in all
block out all
# 锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷息锟斤拷锟斤拷通锟斤拷.
pass in quick on dc0 from 192.168.0.0/24 to any
pass out quick on dc0 from any to 192.168.0.0/24
# 锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷息锟斤拷锟斤拷通锟斤拷.
pass in quick on lo0 all
pass out quick on lo0 all
# 锟斤拷止锟斤拷锟斤拷锟斤拷锟斤拷效锟斤拷址通锟斤拷
block in quick on tun0 from 192.168.0.0/16 to any
block in quick on tun0 from 10.0.0.0/8 to any
block in quick on tun0 from 172.16.0.0/12 to any
block in quick on tun0 from 127.0.0.0/8 to any
block in quick on tun0 from 0.0.0.0/8 to any
block in quick on tun0 from 192.0.2.0/14 to any
block in quick on tun0 from 204.152.64.0/23 to any
block in quick on tun0 from 224.0.0.0/3 to any
# 锟斤拷锟斤拷锟斤拷锟斤拷息锟侥达拷锟斤拷, 锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷锟酵碉拷锟斤拷锟斤拷, 锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷些锟斤拷锟侥伙拷应锟斤拷息通锟斤拷
pass out quick on tun0 proto tcp from any to any flags S/SAFR keep state keep frags
pass out quick on tun0 proto udp from any to any keep state keep frags
pass out quick on tun0 proto icmp from any to any keep state keep frags
锟斤拷锟侥硷拷为NAT锟斤拷锟斤拷锟侥硷拷.
锟斤拷锟斤拷锟斤拷pppoe通锟斤拷DHCP锟斤拷式锟斤拷玫锟街�, 锟斤拷锟斤拷薹锟斤拷诠锟斤拷锟斤拷懈锟斤拷锟斤拷锟斤拷锟斤拷牡锟街�, 锟斤拷锟斤拷0锟斤拷锟斤拷.
# ftp proxy, 为 active 锟斤拷式锟斤拷FTP使锟斤拷, 锟皆猴拷锟斤拷锟斤拷锟斤拷锟斤拷. 锟斤拷注锟斤拷, proxy锟斤拷锟斤拷锟斤拷一锟斤拷要锟斤拷portmap之前.
#map tun0 192.168.0.0/24 -> 0/32 proxy port ftp ftp/tcp
# IKE proxy, 为ESP (Encapsulating Security Protocol) 使锟斤拷
# map tun0 192.168.0.0/24 -> 0/32 proxy port 500 ipsec/udp
# RealAudio proxy, 只锟斤拷锟斤拷锟斤拷PNM模式, RealPlayer G2锟窖撅拷使锟斤拷RTSP.
#map tun0 192.168.0.0/24 -> 0/32 proxy port 7070 raudio/tcp
# 锟斤拷锟斤拷锟节诧拷锟斤拷UDP/TCP锟斤拷通锟斤拷,锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷应锟斤拷通锟斤拷
# 锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷指锟斤拷锟斤拷围锟侥端匡拷
# map tun0 192.168.0.0/24 -> 0/32 portmap tcp/udp 40000:60000
# 锟斤拷锟斤拷锟斤拷锟斤拷系统锟皆讹拷锟斤拷锟斤拷丝锟�
map tun0 192.168.0.0/24 -> 0/32 portmap tcp/udp auto
# 锟斤拷锟斤拷锟节诧拷ICMP通锟斤拷,锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷应锟斤拷通锟斤拷
map tun0 192.168.0.0/24 -> 0/32
# 锟斤拷锟斤拷net2phone, 锟斤拷锟斤拷锟斤拷暮锟斤拷锟阶拷锟街革拷锟斤拷锟斤拷锟�
# rdr tun0 0/0 port 6801 -> 192.168.0.4 port 6801 udp
# 锟斤拷锟斤拷squid
# rdr dc0 0/0 port 80 -> 127.0.0.1 port 3128 tcp
net.inet.ip.forwarding=1
net.inet.ip.sourceroute=0
net.ip.accept_sourceroute=0
# To definding against sequence number attacks
# based on rfc 1948 by randomize initial sequence number
net.inet.tcp.strict_rfc1948=1
# To verisy that an incoming packet arrives on an interface
# that has an address matching the packets destination address
net.inet.ip.check_interface=1
# To Drop SYN packets destine to non-listening tcp/upd port.
# This will create a blackhole and protect against stealth port scans
net.inet.tcp.blackhole=2
net.inet.udp.blackhole=1
# Increase TCP Windows size for increase in network performance
# Ref: http://www.psc.edu/networking/perf_tune.html
net.inet.tcp.recvspace=65535
net.inet.tcp.sendspace=65535
锟睫革拷锟侥硷拷 /etc/resolv.conf, 锟斤拷锟斤拷一锟斤拷
nameserver DNS_SERVER_IP
锟斤拷锟斤拷锟斤拷锟斤拷锟紻NS Server, 应指锟斤拷梅锟斤拷锟斤拷锟�. 锟斤拷锟絞ateway锟斤拷锟斤拷为DNS Server, 为127.0.0.1, 锟斤拷锟斤拷锟斤拷锟斤拷named.conf. 一锟斤拷锟斤拷虻サ锟斤拷锟斤拷镁锟斤拷锟街革拷锟絀SP锟斤拷DNS Server.
锟斤拷锟酵伙拷锟斤拷锟斤拷Gateway 锟斤拷 DNS Server锟斤拷锟斤拷锟斤拷为Gateway锟斤拷锟斤拷锟侥碉拷址 192.168.0.1
Gateway锟睫革拷锟斤拷锟斤拷锟矫猴拷锟斤拷要锟斤拷锟斤拷. 锟斤拷锟斤拷 shutdown -r now
锟酵伙拷锟斤拷Windows XP锟斤拷锟斤拷锟斤拷锟斤拷, Windows 98要锟斤拷锟斤拷.
锟斤拷锟斤拷锟斤拷锟斤拷, 证锟斤拷Windows XP使锟斤拷锟斤拷锟铰癸拷锟竭癸拷锟斤拷锟斤拷锟斤拷.
锟斤拷锟斤拷锟�
target=_blank>http://www.cert.org/security-improvement/practices/p060.html
href="http://web.ranum.com/pubs/fwtest/">http://web.ranum.com/pubs/fwtest/
系统锟斤拷珊锟�, 锟斤拷锟斤拷RealPlayer锟节凤拷锟斤拷墙锟斤拷锟睫凤拷锟斤拷锟斤拷锟斤拷, 锟斤拷锟角诧拷停锟斤拷buffering, 直锟斤拷timeout.
锟斤拷锟斤拷锟斤拷为默锟较凤拷式锟斤拷, RealPlayer8 使锟斤拷锟斤拷UDP Port 6970-7170锟斤拷锟斤拷锟斤拷锟斤拷, 锟斤拷锟斤拷锟捷憋拷锟斤拷锟角的凤拷锟斤拷墙锟斤拷锟斤拷牡锟阶★拷锟�,
锟斤拷锟斤拷NAT锟侥达拷锟斤拷, 锟津单碉拷锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷锟捷帮拷也锟睫凤拷锟斤拷证Client锟斤拷锟斤拷锟斤拷锟斤拷.
ipfilter 锟结供锟斤拷一锟斤拷proxy锟斤拷锟斤拷锟斤拷, 锟斤拷锟斤拷为锟斤拷锟斤拷锟窖撅拷锟叫筹拷锟斤拷锟斤拷, 锟斤拷锟斤拷锟叫癸拷锟斤拷锟斤拷锟斤拷示锟斤拷proxy只支锟街癸拷锟较碉拷 PNM RealAudio锟斤拷式, RealPlayer G2锟窖撅拷使锟斤拷 RTSP 锟斤拷式. 锟斤拷proxy锟斤拷锟斤拷支锟斤拷.
锟斤拷锟斤拷RealPlayer锟结供锟斤拷锟斤拷锟角斤拷锟斤拷莸锟侥Ｊ�, 锟斤拷锟斤拷锟斤拷锟斤拷为只使锟斤拷TCP Port
7070, 7071, 554 锟斤拷锟斤拷锟剿匡拷锟斤拷锟斤拷Server, 锟斤拷锟斤拷锟角的凤拷锟斤拷墙锟斤拷锟斤拷锟角猴拷. 锟节凤拷锟斤拷墙锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷, RealPlayer 8 锟斤拷锟斤拷锟矫凤拷锟斤拷锟斤拷:
锟斤拷锟斤拷锟芥本锟斤拷锟斤拷锟矫凤拷锟斤拷, 锟斤拷锟斤拷锟� target=_blank>http://service.real.com/firewall/adminfw.html
锟斤拷锟斤拷锟叫癸拷QQ锟斤拷锟斤拷谈锟矫很讹拷, 锟斤拷使锟矫碉拷锟斤拷MSN,
锟斤拷哦锟絈Q锟斤拷锟角猴拷锟剿斤拷, 只锟斤拷锟斤拷一锟铰简单的凤拷锟斤拷. 锟斤拷锟斤拷锟较斤拷, 通锟斤拷锟斤拷锟斤拷锟斤拷转锟斤拷锟斤拷锟斤拷锟解发锟斤拷一锟斤拷锟斤拷没锟斤拷什么锟斤拷锟斤拷锟�, 锟斤拷锟斤拷一锟斤拷锟斤拷锟斤拷锟斤拷薹锟斤拷锟斤拷锟斤拷盏锟斤拷苑锟斤拷锟経DP锟斤拷式锟斤拷锟酵碉拷锟斤拷息,
锟斤拷锟斤拷息锟睫凤拷通锟斤拷锟斤拷锟角的凤拷锟斤拷墙.
锟斤拷锟斤拷锟斤拷锟斤拷说锟斤拷锟皆凤拷锟斤拷墙锟斤拷锟斤拷锟斤拷锟斤拷平, 锟斤拷锟斤拷一锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷UDP锟侥帮拷通锟斤拷锟角筹拷锟斤拷. 锟斤拷锟斤拷实锟斤拷锟斤拷锟斤拷NAT锟斤拷, 锟斤拷锟斤拷使锟斤拷锟斤拷192.168.0.0/16锟斤拷锟斤拷锟斤拷锟节诧拷锟斤拷址. 锟斤拷QQ锟斤拷锟斤拷锟斤拷锟阶拷锟绞�, 实锟斤拷使锟矫碉拷锟斤拷Gateway锟侥碉拷址, 锟斤拷锟斤拷锟斤拷锟斤拷诓锟斤拷卸锟斤拷锟斤拷使锟斤拷QQ,
锟斤拷锟斤拷锟斤拷也锟斤拷锟斤拷锟叫㏎Q锟斤拷锟斤拷锟斤拷锟接碉拷锟斤拷锟絀P锟斤拷, 锟斤拷锟斤拷锟矫伙拷锟斤拷锟捷凤拷锟斤拷锟斤拷锟结供锟侥碉拷址锟斤拷锟解部锟斤拷锟斤拷UDP锟斤拷锟斤拷锟斤拷Gateway,
Gateway锟酵诧拷知锟斤拷应锟矫帮拷锟斤拷息转锟斤拷锟斤拷谁. 锟斤拷锟斤拷獠拷锟斤拷锟揭伙拷锟斤拷虻サ锟斤拷锟斤拷锟斤拷锟斤拷莅锟酵拷锟斤拷锟斤拷锟斤拷锟�. 锟斤拷锟斤拷锟酵拷锟斤拷锟斤拷饣癸拷锟絥etmeeting. 锟斤拷锟斤拷姆锟斤拷锟�, 一锟斤拷锟斤拷锟斤拷锟矫伙拷全锟斤拷通锟斤拷锟斤拷锟斤拷锟斤拷转锟斤拷, 锟斤拷锟斤拷墙锟杰癸拷锟杰好地达拷锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷. 锟斤拷锟斤拷锟斤拷MSN锟斤拷锟斤拷锟斤拷么锟斤拷锟斤拷. 锟斤拷锟斤拷锟斤拷要QQ
service provider锟侥猴拷锟斤拷, 锟斤拷锟揭讹拷锟斤拷锟角的凤拷锟斤拷锟斤拷锟斤拷锟叫革拷锟竭碉拷要锟斤拷. 锟斤拷一锟街凤拷锟斤拷锟斤拷锟斤拷锟斤拷ftp client锟侥斤拷锟斤拷锟绞�, 锟斤拷Gateway锟斤拷锟斤拷锟斤拷proxy. 锟斤拷没锟斤拷QQ锟斤拷锟斤拷锟斤拷, 锟斤拷锟斤拷锟斤拷锟铰斤拷锟斤拷.
FTP协锟斤拷
锟斤拷锟斤拷一锟斤拷锟斤拷锟斤拷FTP协锟斤拷锟斤拷锟斤拷傻锟斤拷锟斤拷锟�, 锟斤拷锟斤拷锟斤拷锟饺匡拷一锟斤拷FTP协锟斤拷.
FTP一锟斤拷锟斤拷要使锟斤拷锟斤拷锟斤拷锟剿匡拷, 锟剿匡拷21只锟斤拷一锟斤拷锟斤拷锟斤拷丝锟�, 锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷锟捷碉拷时锟斤拷, 锟斤拷锟斤拷要锟斤拷锟斤拷一锟斤拷锟斤拷锟捷端匡拷. 锟斤拷锟斤拷统锟斤拷锟斤拷诘诙锟斤拷锟斤拷锟斤拷荻丝锟斤拷锟�.
锟斤拷锟斤拷锟斤拷锟斤拷荻丝诘锟绞憋拷锟斤拷锟斤拷锟斤拷址锟绞�, 一锟斤拷锟斤拷passive(PASV command)锟斤拷式, 锟斤拷FTP Server锟斤拷锟结供一锟斤拷锟斤拷锟接碉拷IP/Port, FTP
Client锟斤拷锟接碉拷锟斤拷锟絀P/Port锟较斤拷锟斤拷锟斤拷锟捷达拷锟斤拷. 锟斤拷一锟斤拷锟斤拷active(PORT command)锟斤拷式, 锟斤拷FTP Client锟结供IP/Port,
锟斤拷锟斤拷FTP Server锟截斤拷锟斤拷Client锟结供锟侥碉拷址. 锟斤拷锟斤拷锟斤拷锟斤拷锟揭伙拷址锟绞�, 锟斤拷锟斤拷FTP
Client锟斤拷锟斤拷锟斤拷, Client通锟斤拷PASV锟斤拷PORT锟斤拷锟斤拷通知Server锟斤拷锟斤拷什么锟斤拷式. 锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷锟街凤拷式, 锟斤拷Server锟剿猴拷Client锟剿讹拷锟斤拷锟斤拷锟斤拷榉�. 锟斤拷锟斤拷锟斤拷锟侥撅拷锟斤拷锟斤拷锟斤拷锟斤拷锟�
target=_blank>http://www.daemonnews.org/200109/ftpnat.html
FTP Server
Server锟斤拷一锟姐不希锟斤拷使锟斤拷passive锟斤拷式, 锟斤拷锟街凤拷式要锟斤拷锟斤拷锟角斤拷锟教拷卮锟絇ASV锟侥端匡拷.
锟斤拷active锟斤拷式锟斤拷锟斤拷Server锟侥凤拷锟斤拷墙没锟斤拷什么锟斤拷锟斤拷锟揭拷锟�. 锟斤拷锟斤拷FTP
Server锟角诧拷锟斤拷选锟斤拷锟�, 锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷支锟斤拷passive锟斤拷式. 一锟斤拷慕锟斤拷锟斤拷锟斤拷锟斤拷, 锟节凤拷锟斤拷墙锟较固讹拷锟截达拷一些锟剿匡拷, 锟斤拷 15001-19999, 每锟斤拷通锟斤拷, FTP
Server锟斤拷锟斤拷锟斤拷锟皆达拷锟斤拷些锟剿匡拷锟斤拷选锟斤拷一锟斤拷锟斤拷为PASV锟侥端匡拷通知FTP Client. 锟斤拷锟斤拷锟斤拷FTP
Server锟斤拷支锟斤拷指锟斤拷passive锟剿口凤拷围, 锟斤拷应锟矫匡拷锟角革拷锟斤拷FTP Server锟斤拷. 锟斤拷锟街凤拷式锟斤拷锟斤拷墙锟斤拷要锟斤拷锟接癸拷锟斤拷
pass in quick on tun0 proto tcp from any to 0/32 port 15000>< 20000
flags S keep state keep frags
FTP Client
锟斤拷锟斤拷锟斤拷锟斤拷锟叫拷锟斤拷锟斤拷, 锟斤拷锟紽TP Client锟斤拷锟斤拷passive锟斤拷式, 锟斤拷锟节凤拷锟斤拷墙锟斤拷锟斤拷没锟斤拷什么锟斤拷锟斤拷锟揭拷锟�, 锟斤拷锟角匡拷锟皆帮拷锟斤拷锟斤拷锟斤拷锟斤拷FTP Server.
锟斤拷锟斤拷息锟角ｏ拷一锟斤拷锟紽TP Client锟斤拷锟斤拷锟斤拷支锟斤拷passive锟斤拷式, 锟斤拷使锟矫碉拷锟斤拷锟斤拷锟斤拷锟斤拷(netant), 锟斤拷锟绞快车(FlashGet)默锟较凤拷式锟斤拷锟斤拷passive,
WS_FTP锟角匡拷锟斤拷锟斤拷锟矫碉拷, 锟斤拷锟斤拷锟斤拷锟斤拷墙锟酵诧拷锟斤拷要锟斤拷锟解处锟斤拷锟斤拷. Unix锟斤拷锟斤拷要锟斤拷锟斤拷
FTP_PASSIVE_MODE=yes; export FTP_PASSIVE_MODE
锟斤拷锟斤拷息锟斤拷, 锟斤拷锟斤拷锟斤拷锟紽TP使锟矫碉拷锟斤拷active锟斤拷式, 锟斤拷锟揭猴拷锟今还诧拷锟杰革拷锟斤拷. 锟斤拷锟斤拷锟斤拷锟斤拷直锟斤拷使锟斤拷锟斤拷锟斤拷锟紽TP锟斤拷锟斤拷锟窖撅拷锟角猴拷锟斤拷锟斤拷
------ 锟揭达拷锟斤拷锟酵诧拷锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷锟�.
锟斤拷锟斤拷, 锟斤拷一些FTP站锟斤拷, 锟斤拷支锟斤拷passive锟斤拷式. 锟斤拷锟斤拷锟斤拷锟斤拷锟绞癸拷一些私锟剿碉拷FTP站锟斤拷, 锟斤拷锟睫凤拷使锟斤拷passive锟斤拷锟斤拷, 也锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷品锟斤拷锟角斤拷锟绞憋拷锟矫伙拷锌锟斤拷前锟�.
支锟斤拷active模式锟斤拷锟斤拷通锟斤拷锟斤拷NAT锟斤拷锟斤拷锟斤拷proxy锟斤拷锟斤拷锟�. Linux通锟斤拷锟斤拷锟斤拷ip_conntrack_ftp锟斤拷锟�, ipnat锟窖撅拷锟斤拷锟斤拷锟斤拷锟揭伙拷锟斤拷锟�, 锟斤拷锟斤拷只锟斤拷要锟斤拷锟斤拷一锟斤拷锟斤拷锟斤拷涂锟斤拷锟斤拷锟�.
锟角撅拷锟斤拷锟斤拷前锟斤拷ipnat.conf锟叫的碉拷一锟斤拷锟斤拷锟斤拷. 锟斤拷proxy锟斤拷锟皆伙拷锟结供锟斤拷锟斤拷FTP锟斤拷锟斤拷, 锟斤拷锟斤拷FTP Server. 锟斤拷惜锟斤拷锟斤拷, 锟斤拷锟斤拷锟叫匡拷锟斤拷锟斤拷砂锟饺拷锟斤拷锟斤拷锟斤拷锟斤拷
target=_blank>http://www.false.net/ipfilter/2001_11/0273.html.
锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷一些ipfilter锟斤拷使锟斤拷锟斤拷锟斤拷锟桔癸拷锟斤拷锟斤拷锟斤拷锟�, 一锟斤拷锟斤拷为, 锟斤拷锟絞ateway锟斤拷锟斤拷锟斤拷锟斤拷锟紽TP Server, 锟斤拷要锟斤拷锟斤拷锟结供FTP锟斤拷锟斤拷幕锟�, 锟斤拷没锟斤拷遣锟揭拷锟斤拷锟斤拷锟揭籶roxy, 锟节诧拷锟矫伙拷只锟斤拷锟斤拷使锟斤拷passive锟斤拷式.
锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷锟揭伙拷锟斤拷锟斤拷锟侥达拷锟斤拷锟斤拷锟斤拷锟斤拷, 锟斤拷FTP只锟斤拷锟节诧拷锟斤拷锟斤拷锟斤拷锟斤拷, 锟斤拷锟斤拷锟斤拷一proxy应锟斤拷锟角帮拷全锟斤拷.